[RE-wrenches] Surrette Battery Question

[Drake Chamberlin]

Hi Allan,

On a previous thread, it seems that Surrette batteries like a fast 
charge periodically.  At one time (as I recall) is was recommended to 
give them a C/5 once a week, but the company said that was not 
necessary.  I don't know of C/13 to C/18 charges would be 
enough.  Can your customer run the generator for a quick charge after 
cycling them down?

Drake

At 08:29 AM 8/2/2008, you wrote:
>Did this customer check the voltage of the individual 
>batteries/cells? Maybe there is a weak cell developing. Sometimes 
>EQing can take a long time. I do not "buy" that batteries need to be 
>cycled to stay healthy.
>
>Todd
>
>jay peltz wrote:
>
>>Hi Robert,
>>
>>When you mention cycling batteries, are you saying that batteries 
>>in a offgrid system that are being cycled 15-25% a day should be 
>>cycled even deeper than that?
>>
>>Thanks,
>>
>>jay peltz power
>>On Aug 1, 2008, at 8:36 PM, robert ellison wrote:
>>
>>>A couple things that I haver noticed in the past, sometimes 
>>>batteries like to be cycled, shut off the controllers and run them 
>>>down, then charge them up fully and then give them an eq charge 
>>>till it comes up the peak voltage and hold it there as it 
>>>(sometimes) slowly rises. Any of these thoughts are superseded by 
>>>Jamie if he has any thoughts.  Also, if you have not given them an 
>>>eq in a while it might take longer than the available solar time 
>>>has to get them to the top and hold them there..
>>>Have the controllers settings changed?
>>>
>>>Bob
>>>On Fri, Aug 1, 2008 at 10:18 PM, Allan Sindelar 
>>><allan at positiveenergysolar.com <mailto:allan at positiveenergysolar.com>> wrote:
>>>
>>>     Wrenches,
>>>     In late 2003 we installed a 24V set of Rolls-Surrette 4-KS-21PS
>>>     6V 1104 A/hr batteries in the off-grid system of a long-time
>>>     client. The client's system had a democracy array of around 800
>>>     watts of tracked PV. In early 2005 we added 1,280 watts of
>>>     additional PV, and the client hasn't run the generator since; the
>>>     system rarely drops below 80% and fills to 100% most days in
>>>     sunny New Mexico. Batteries are located in a basement, so
>>>     temperatures stay relatively constant, although it will vary
>>>     slightly seasonally. MX60 controller is temperature compensated,
>>>     with 29.6 VDC bulk and 31.4 VDC EQ set points.
>>>
>>>     The problem is that the client reports being unable to achieve
>>>     previous EQ voltages, and this inability appears to be a new
>>>     development. The system is otherwise performing well. As the
>>>     client is sharp and pays close attention to the system's
>>>     operation, I'm not ready to blame user ignorance (with one
>>>     possible exception; read on). This may be an issue of seasonally
>>>     warm temperatures, but I'm not sure this would explain the full
>>>     0.4 VDC reduction in voltage. I told him that I would post his
>>>     problem to this list, and also request advice from Surrette Battery.
>>>
>>>     Here is the client's description of the symptoms:
>>>     I'm concerned that I am unable to equalize batteries at this
>>>     time.  Up
>>>     until June of this year the Tri-Metric readings during equalizing
>>>     indicated
>>>     holding voltage at 31.1, with maximum amps gain of around 52.
>>>     Three weeks
>>>     ago, when set on equalize, the maximum voltage reading was 30.7,
>>>     with
>>>     maximum amps of 46; this was reached around noon, and by around
>>>     1:30 pm
>>>     voltage/amps began its typical afternoon drop-off.  I attempted
>>>     equalizing
>>>     on two other occasions since then--the last time this past
>>>     Saturday, with
>>>     clear skies up until mid-afternoon--but having the same 
>>> results.     So, the
>>>     question is: are my batteries beginning their decline? We've had
>>>     this set
>>>     for 4 1/2 years, so it would seem a bit too early for this, given
>>>     that these
>>>     batteries are expected to last 7-10 years.
>
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Drake Chamberlin
Athens Electric
OH License 44810
CO License 3773
740-448-7328
303-328-5533